Yamaha XF50W Service Manual page 260

Fault code No. 21
Used diagnostic code No. D06 (coolant temperature sensor)
Inspection operation item and
Order
probable cause
1 1 1 1 Installed condition of sensor
2 2 2 2 Connected condition of con-
nector
Inspect the coupler for any
pins that may have pulled
out.
Check the locking condition
of the coupler.
3 3 3 3 Open or short circuit in wiring
harness.
4 4 4 4 Defective coolant temperature
sensor.
FUEL INJECTION SYSTEM
Symptom Coolant temperature sensor open or short circuit is detected.
Operation item and countermeasure
Check the installed area for looseness or
pinching.
If there is a malfunction, repair it and connect
it securely.
Coolant temperature sensor coupler
Main wiring harness ECU coupler
Repair or replace if there is an open or short
circuit.
Between sensor coupler and ECU coupler
black/blue-black/blue
green/red - green/red
Execute the diagnostic mode (code No.D06)
Replace if defective.
Refer to "COOLING SYSTEM" in chapter 8.
7-17
FI ifl
Reinstatement
method
Reinstated by turn- Reinstated by turn- Reinstated by turn- Reinstated by turn-
ing the main switch ing the main switch ing the main switch ing the main switch
ON. ON. ON. ON.